The present invention concerns a busbar bushing device adapted to be mounted through an orifice formed in a wall for a conductive busbar to pass through, of the type including a body through which a conduit for receiving said busbar passes completely and a cover attached to said body, said cover including an opening through which said busbar passes and which is aligned with the conduit in the body.
It also concerns a bar lead-in.
Busbar bushing devices are used to pass an electrical line, in particular a high-current line, through a wall, for example a wall of a transformer housing.
Bar lead-ins are therefore formed of a busbar bushing device and a conductive busbar. For busbars of oblong section, and in particular of substantially rectangular section, busbar bushing devices are currently made of plastics material. The bar lead-in must be used under a cover or inside a part protected from inclement weather, the materials used in prior art structures having poor resistance to external attack. In particular, said busbar bushing devices do not provide an adequate seal.
Prior art bar lead-ins that withstand exposure to inclement weather out-of-doors include busbar bushing devices, known in this case as rod bushing devices, made of porcelain. Because of how they are made, these rod bushing devices accept only a circular section conductive rod. Moreover, they are costly. Finally, they are fragile and cannot withstand significant bending of the conductive rod.
An aim of the invention is to propose a low-cost busbar bushing device that can be exposed to inclement weather out-of-doors and can receive a busbar of oblong, in particular rectangular, section.
To this end, the invention consists in a busbar bushing device of the aforementioned type characterized in that the opening in the cover is bordered externally by an elastically deformable peripheral lip adapted to be pressed in a sealed manner all around the contour of the conductive busbar.
In particular embodiments of the invention, the busbar bushing device has one or more of the following features:
the lip is in one piece with at least part of the cover;
the cover has a rigid inner structure and the lip is moulded onto said rigid structure;
the lip is in one piece with an insulative coating covering at least the greater part of the outside surface of the cover;
said passage and the opening have substantially identical oblong sections;
the body has, in a region covered by the cover, a transverse bore opening into said passage, which bore is adapted to receive a pin for retaining the conductive busbar which itself includes a bore for the end of the pin, the cover trapping the pin when fitted to the body;
the body has a peripheral flange adapted to bear on one face of the wall, the cover includes means for fixing it to the wall and is in the form of a cap covering at the same time the greater part of the body and the peripheral flange, and an O-ring is disposed around the peripheral flange, against the wall, in a housing in the cover;
the cover includes a housing to receive the greater part of the body, the housing being extended by the opening, and the housing includes, over at least a part of its length, a portion which has a section which increases progressively towards the opening and which is adapted to guide an O-ring disposed between the body and the cover and to compress it in the housing when fitting the cover to the body.
The invention further consists in a bar lead-in characterized in that it includes a conductive busbar and a busbar bushing device as defined hereinabove.